SMB MAT-LC-C Series User Manual page 64

Implicit variables can also be accessed by other programs, for example, boolvar1:=sfc1.step1.x;
where step1.x is an implicit boolean variable, which represents the state of IEC step step1 in
POUsfc1.
SFC designator
Identifiers are used to control the operation of SFC POUs and are implicitly created during
project operation. In order to be able to read these identifiers, appropriate global or local
variables must be defined. For example, if a step in an SFC POU is active longer than its defined
properties, then a flag is set, which can be accessed by using a "SFCError" variable (in which
case SFCError gets true).
The following identifier variables can be defined:
SFCEnableLimit: The type of this variable is Boolean. When its value is TRUE, the timeout of this
step will be registered in SFCError, and other timeouts will be ignored.
SFCInit: When the value of this Boolean variable is TRUE, the SFC is reset to its initial state, and
other SFC identifiers are also reset. The initial step remains active until the variable value is
TRUE, and execution begins. The module works correctly only when SFCInit is reset to FALSE.
SFCReset: This boolean variable is very similar to SFCInit, except that further processing takes
place after the initialization of the initialization step, thus, for example, the SFCReset flag can be
reset to FALSE during the initialization step.
SFCQuitError: When this boolean variable gets TRUE, the execution of the SFC will be stopped,
so a possible timeout in the variable SFCError will be reset, when this variable is FALSE, all
times in the active step will be reset, the precondition is that in the SFC SFCError is pre-defined
in , and the flags for any timeout settings are registered.
SFCPause: When this boolean variable is TRUE, the SFC chart stops executing.
SFCError: This variable gets TRUE when there is a timeout in the SFC chart. If other timeouts
occur after this one, these states will not be recorded unless this variable has been reset. If you
want to use other time control flags (SFCErrorStep, SFCErrorPOU, SFCQuitError,
SFCErrorAnalyzation) the precondition is to define SFCError.
SFCTrans: This boolean variable gets true when a transition is activated.
SFCErrorStep: This variable is a string variable. If a timeout is registered in SFCError, this
variable will store the name of the timeout step. The precondition is that the flag SFCError to
register any timeout has been defined in the SFC.
SFCErrorPOU: This string variable contains the name of the module where the timeout occurred.
The precondition is that the flag SFCError to register any timeout has been defined in the SFC.
SFCCurrentStep: This string variable stores the name of the active step, it is not related to time
monitoring. In the case of simulation, this step is stored in the branch of external authority. If a
timeout occurs, the timeout will no longer be registered and SFCError will not be reset.
SFCErrorAnalyzationTable: This is an array variable ARRAY[0..n] that provides the analysis
result of a conversion expression. For each element that has an effect, the conversion is
registered as FALSE, and the previous step time-out record, so write the following information
into the ExpressionResult structure, write: name, address, comment, current value.
A maximum of 16 elements can be held, so the range of the array is from (0~15).
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